You can easily change the email address that's on file for your Quicken account by signing in to myaccount.quicken.com. Here, you can manually change your email address, password, and other personal information. You can click here for more details!
However, if you no longer have access to the email address that's associated with your Quicken ID and are unable to sign into your Quicken account, you can use the following form to submit a request to change your email address for Quicken: https://www.quicken.com/support/e-mail-change-request-submission.
Note: The email address change request form is Quicken-based, as your Quicken ID and Quicken LifeHub username (email address) are one and the same.
The form requires that proof of your identity be attached, so please be sure to grab a photo of your Driver's License, State Issued ID, or another form of acceptable proof before submitting the form. Once submitted, you'll see a pop-up success message.
Please allow 24 to 48 hours for the change to be processed.
What if I don't know the old email address I used?
When submitting the Email Change form, if you're unsure of your old email address, or think there was a typo, just do your best to enter what you think it should be, and then add a note under "Why are you requesting this change?" stating that you're unsure of the old email address.